Is it permissible for a lady to be in bikini next to a non Jew. For example, next to the lifesaver, o two or three other goyim. She’s not trying to call their attention, she’s not parading. Thanks.
While the same restrictions of tznius do not apply when only non Jewish men are present, and some leniency may be applied, it would seem the behavior you mention is not appropriate. Extreme immodesty in the presence of men can lead to many breakdowns of tznius barriers between men and women, and lead to much more severe prohibitions. Aside from the negative effect such behavior may have on her own self respect and tznius standards. In such a scenario one can easily raise their tznius standards with more modest swim wear.